No external disks will mount except external SSD boot drive.

[Smarky]

Hi all,

My internal SSD failed, so I got an external SSD drive and since then I have had rather odd issues.

Currently no external drive will mount, these are external hard drives and flash drives in various formats, all of these work on another device and in Recovery mode.

They are seen in system report, they even have a disk number and it identifies the drive, they do not show up in disk utility.

I installed WD utilities for one of the drives, that shows up in the utility and I can run full diagnostics on the drive, comes back fine, but still cannot mount.

All drives work in Previous versions of MacOS prior to Monterey, from Monterey onwards this issue exists. Monterey also had the issue where no Disk images would mount, even DMG files and nither would my SD card, this was fixed by upgrading to Ventura, but I still cannot mount any external drives.

I've tried this on a fresh install, completely wipping the drive but still doesn't work. I am booting from an SSD via usb3.

 

[DeltaMac]

Do any of those drives show in the terminal after running

diskutil list

 

[Smarky]

Do any of those drives show in the terminal after running

diskutil list

Nope, sadly diskutil doesn't see anything at least in the normal OS.

Shows them all fine in Recovery mode. I've tried to mount them using terminal and the Disk numbers in system report, but doesn't work either.

 

[Fishrrman]

Another Fishrrman "stupid question™":

Have you gone to the finder, gone to preferences -> general,
And clicked the boxes to show hard disks, external disks, etc. on the desktop?

Also, can you tell us what Mac you have and WHAT YEAR it was made?
Can you tell us WHAT FORMAT the external drives are in?

 

[DeltaMac]

You said the internal SSD failed.
Have you removed that dead internal SSD?
Do the built-in diagnostics report any issues?

After Monterey, you would look in Finder for Settings, not Preferences (if that is a question for you)

You also said that you can see drives in recovery mode.
Can you also see drives when you boot to Safe Boot mode?
(Restart while holding your Shift key.)

 

[Smarky]

Another Fishrrman "stupid question™":

Have you gone to the finder, gone to preferences -> general,
And clicked the boxes to show hard disks, external disks, etc. on the desktop?

Also, can you tell us what Mac you have and WHAT YEAR it was made?
Can you tell us WHAT FORMAT the external drives are in?

Drives are NTFS, AFS, ExFat and Fat32, just about every format really. I have a lot of different drives I have tested.
iMac 2015.

I have gone into preferences and set everything.

 

[Smarky]

You said the internal SSD failed.
Have you removed that dead internal SSD?
Do the built-in diagnostics report any issues?

After Monterey, you would look in Finder for Settings, not Preferences (if that is a question for you)

You also said that you can see drives in recovery mode.
Can you also see drives when you boot to Safe Boot mode?
(Restart while holding your Shift key.)

Have not removed failed SSD, it's a build to order Mac which I believe means it is behind the logic board, I went for an external SSD as I didn't want to risk opening the iMac at this point, I need it and use it as a Monitor for my windows machine. The failed SSD is not recognised at all in System report.

Drives do not show in Safe mode.

 

[Smarky]

Just to add more context for everyone, thanks for your help, I also have another issue, where bluetooth doesn't enable until about 10 minutes after login and then it works fine.

If I go into System report and go into bluetooth, no bluetooth adapter is listed, but when it comes on, it is suddenly listed. This seems to happen on the same versions of OS that have the issue reading external drives.

Basically my issues are:
Pre-Monterey: Everything works.
Monterey: Bluetooth takes ten minutes to turn on, unable to mount disk images (DMG files), unable to mount external drives, no sd card.
Ventura and Somona : Disk images mount (DMG files), SD card is readable and mounts but bluetooth and external drive issue remains.

Ventura and Somona have been installed via OpenCore legacy patcher as my Mac isn't supported, but it seems to improve things rather than making it worse. The issue doesn't seem to with Opencore.

The Monterey issue where it doesn't mount DMG files, seems to be an issue with DiskImageMounter, if I swap it out for one from an older OS, DMG files mount fine.

 

[Smarky]

To add more bizarre behaviour to this: I've installed Parallels and have it running Ventura.

THIS MOUNTS THE DRIVES that the host OS will not.

What the heck is going on!? If I direct boot this OS it does not!

 

[chown33]

I wouldn't rule out OCLP entirely. The OS isn't supported for that machine, and there may be some new thing relating to USB security or boot drive security that could be affecting things.

I took a look at the iFixit guide for the iMac 2015, and it's a big PITA to remove the builtin SSD. At least it's on a removable blade / card, rather than being soldered in.

What I haven't been able to determine is what bus the internal SSD is on. If it's USB, then having the SSD present and non-functional could be interfering with other things on USB.


I'm pretty sure the internal Bluetooth radio is on USB. You should be able to check that using System Profiler or System Info and looking at the USB section of the Hardware heading.

The 10-minute delay on BT working seems odd, unless it's again related to some increased bus security in the more recent OS.

I don't recall if builtin SSDs default to a sleep delay or not. If so, and that delay is 10 mins, then maybe that's a coincidence worth looking at. E.g. try changing it to 15 min and see if the BT delay tracks.


The fact that Ventura under Parallels can see and mount the drives makes me think it's a software problem with either OCLP or the later OS that's preventing things from working. I'm blindly guessing it might be a security restriction, since later OS versions have increasingly added security to the boot process, like signed boot vols, firmware, read-only boot vols, etc.

 

[Smarky]

I wouldn't rule out OCLP entirely. The OS isn't supported for that machine, and there may be some new thing relating to USB security or boot drive security that could be affecting things.

I took a look at the iFixit guide for the iMac 2015, and it's a big PITA to remove the builtin SSD. At least it's on a removable blade / card, rather than being soldered in.

What I haven't been able to determine is what bus the internal SSD is on. If it's USB, then having the SSD present and non-functional could be interfering with other things on USB.


I'm pretty sure the internal Bluetooth radio is on USB. You should be able to check that using System Profiler or System Info and looking at the USB section of the Hardware heading.

The 10-minute delay on BT working seems odd, unless it's again related to some increased bus security in the more recent OS.

I don't recall if builtin SSDs default to a sleep delay or not. If so, and that delay is 10 mins, then maybe that's a coincidence worth looking at. E.g. try changing it to 15 min and see if the BT delay tracks.


The fact that Ventura under Parallels can see and mount the drives makes me think it's a software problem with either OCLP or the later OS that's preventing things from working. I'm blindly guessing it might be a security restriction, since later OS versions have increasingly added security to the boot process, like signed boot vols, firmware, read-only boot vols, etc.

The Bluetooth is on the USB bus, so this does suggest issues here. It lists it under USB and is found even for the ten minutes that it doesn't work, although for those ten minutes going into system report under bluetooth it lists 'null'

I get OCLP causing issues, but I am getting the same problem (and worse with Monterey without OCLP), I'm happy to test anything on Monterey as well as I have that on a separate drive.

It does seem to me that it might be a security/permission error. The old SSD is not shown in system report at all, it seems to be completely dead.

 

[chown33]

The Bluetooth is on the USB bus, so this does suggest issues here. It lists it under USB and is found even for the ten minutes that it doesn't work, although for those ten minutes going into system report under bluetooth it lists 'null'

I get OCLP causing issues, but I am getting the same problem (and worse with Monterey without OCLP), I'm happy to test anything on Monterey as well as I have that on a separate drive.

It does seem to me that it might be a security/permission error. The old SSD is not shown in system report at all, it seems to be completely dead.

Each macOS version's sub-forum has a stickied thread named "OS_VERSION on Unsupported Macs" that covers the various Macs and the use of OCLP to get them running a particular OS version:

macOS

forums.macrumors.com

You might find some specific info on USB in one of those threads. If you ask for help on one of those, you don't have to copy and paste everything, just link to this thread (or your other BT thread) for users to read the details.


You wrote:

iMac 2015

Is that the year you acquired it, or the actual release year?

I'm asking because I see two models of iMac that might have been purchased in 2015. One is the "Mid 2014" model iMac 14,4. The other is the "Late 2015" model iMac 16,1 released 13 Oct 2015. It would probably help clarify exactly what you have by listing the "iMac N,M" identifier.

The iMac 14,4 model falls under "Early Intel Macs", which has a sub-forum:

Early Intel Macs

Core 2 Duo, Core Duo, Core Solo machines

forums.macrumors.com

I used this Wikipedia article to find which iMac model was released when:

iMac (Intel-based) - Wikipedia

en.wikipedia.org

 

[Smarky]

Each macOS version's sub-forum has a stickied thread named "OS_VERSION on Unsupported Macs" that covers the various Macs and the use of OCLP to get them running a particular OS version:

macOS

forums.macrumors.com

You might find some specific info on USB in one of those threads. If you ask for help on one of those, you don't have to copy and paste everything, just link to this thread (or your other BT thread) for users to read the details.


You wrote:

Is that the year you acquired it, or the actual release year?

I'm asking because I see two models of iMac that might have been purchased in 2015. One is the "Mid 2014" model iMac 14,4. The other is the "Late 2015" model iMac 16,1 released 13 Oct 2015. It would probably help clarify exactly what you have by listing the "iMac N,M" identifier.

The iMac 14,4 model falls under "Early Intel Macs", which has a sub-forum:

Early Intel Macs

Core 2 Duo, Core Duo, Core Solo machines

forums.macrumors.com

I used this Wikipedia article to find which iMac model was released when:

iMac (Intel-based) - Wikipedia

en.wikipedia.org

Hello,

It is a late 2015 iMac, 17,1 rather than 16,1 in that article.

Each macOS version's sub-forum has a stickied thread named "OS_VERSION on Unsupported Macs" that covers the various Macs and the use of OCLP to get them running a particular OS version:

macOS

forums.macrumors.com

You might find some specific info on USB in one of those threads. If you ask for help on one of those, you don't have to copy and paste everything, just link to this thread (or your other BT thread) for users to read the details.


You wrote:

Is that the year you acquired it, or the actual release year?

I'm asking because I see two models of iMac that might have been purchased in 2015. One is the "Mid 2014" model iMac 14,4. The other is the "Late 2015" model iMac 16,1 released 13 Oct 2015. It would probably help clarify exactly what you have by listing the "iMac N,M" identifier.

The iMac 14,4 model falls under "Early Intel Macs", which has a sub-forum:

Early Intel Macs

Core 2 Duo, Core Duo, Core Solo machines

forums.macrumors.com

I used this Wikipedia article to find which iMac model was released when:

iMac (Intel-based) - Wikipedia

en.wikipedia.org

I will have a poke around the OCLP threads, although it doesn't seem to be an OCLP issue, I've just tested booting Monterey with a Monterey also in parallels, works in parallels not in the standard OS.

 

[Fishrrman]

OCLP?
Then... no wonder things may not be "working right"...

 

[Smarky]

OCLP?
Then... no wonder things may not be "working right"...

Nope.

You've missed the part where I say I get the same problems with Monterey without any form of OCLP, but even worse. I understand, this is a complex issue so lots of word soup in this thread

Using OCLP was just an experiment. It actually fixes some things because Monterey is part of the issue, I will happily go back fully to Apple's fully supported version if I can get it working correctly.

 

[Fishrrman]

Just some thoughts.
Probably don't mean anything.

First... I'd STOP USING bluetooth... forever.
(I live by the advice I offer, as well.)
BT is a "weak radio" technology that seems to generate much more than its fair share of problems for Mac users.

Just use "wired" and be done with it.
Or use Logitech devices with Logitech's own "unifying receiver" radio tech.

Next...

Try connecting the drives that won't mount through a POWERED hub.
(you may already be doing this, but if you're not, give it a try).
Non-powered won't do. Again, it must be a powered hub with its own power supply block.

Another thought...
The problem drives... what happens if you connect them to A DIFFERENT Mac?
Same issues?

 

[Smarky]

Just some thoughts.
Probably don't mean anything.

First... I'd STOP USING bluetooth... forever.
(I live by the advice I offer, as well.)
BT is a "weak radio" technology that seems to generate much more than its fair share of problems for Mac users.

Just use "wired" and be done with it.
Or use Logitech devices with Logitech's own "unifying receiver" radio tech.

Next...

Try connecting the drives that won't mount through a POWERED hub.
(you may already be doing this, but if you're not, give it a try).
Non-powered won't do. Again, it must be a powered hub with its own power supply block.

Another thought...
The problem drives... what happens if you connect them to A DIFFERENT Mac?
Same issues?

I use bluetooth headphones as wireless headphones are needed, however I do use Logitech keyboard and mouse so I switched to the unifying receiver to solve this issue. The bluetooth problem isn't really a massive bother, more including it to help troubleshoot.

All the drives work fine on another other Mac or Windows machine, I've tried about a half dozen or more USB hard drives/flash drives, all of them work on older MacOS or other machines without issue.

Powered hub was my next thought too, I'm trying to source one to test, the external usb SSD that I am booting from is not externally powered, so was partly wondering about it being a power issue however that wouldn't explain why it works fine on the same Mac in Windows, in Parallels running instead the same MacOS system that doesn't see it or in any older MacOS.

From searching Apple forums etc though, I did come across someone that was advised by Apple support who had this issue with a certain drive, to plug it into a hub. I currently only have a non-powered one which when used still has the same behaviour.

 

[Fishrrman]

There's something called an "SMC reset" (serial port management, I think).
How it's reset depends upon which Mac you have.
Might be worth a try.